Mr Massey says the meteor strike has left the biggest known human injury toll from a space rock.

"I am scratching my head to think of anything in recorded history when that number of people have been indirectly injured by an object like this ... it's very, very rare to have human casualties," he said.

He says small space debris burns up harmlessly in the sky as it enters the atmosphere, appearing in streaks of light called meteors that can often be seen on a clear night.

But, very rarely, larger objects survive the early stage of descent before exploding in the lower atmosphere, causing a shockwave, which is what happened on Friday, Mr Massey says.